When installing Kentico CMS on a Remote server using a project created by the web installer or when running from a source code package, you may encounter an Internal Server Error while starting the Database setup. This occurs if the application pool of your IIS application is set for .NET 4.0 and Integrated managed pipeline mode (on IIS 7.0 or higher).
It is caused by the fact that your web.config file is not configured for Integrated pipeline mode by default. The application pool mode can be selected in the web installer during the course of an installation to a local IIS server, which causes the correct web.config to be created, but this is not the case when creating a project for a remote server or when using a project from a source code package.
The solution is to replace the default web.config file of your project with one containing the necessary configuration. The appropriate files can be downloaded here:
Page url: http://devnet.kentico.com/docs/5_5r2/devguide/index.html?error_integrated_pipeline_mode.htm